1) Field of the Invention
The present invention relates to a wireless in-vivo information acquiring system, a body insertable device, and an external device.
2) Description of the Related Art
In the field of endoscopes, swallowable capsule-type endoscopes (hereinafter, “pill”) have been on the market in recent years. The pill includes an imaging function and a wiring function. The pill has a mechanism such that the pill is swallowed by a patient for observation (diagnosis), travels along the inside of organs of the patient such as stomach and small bowel due to peristalsis of the organs, and successively imaging the inside of the organs in an observation period since the pill is swallowed until it is naturally excreted from the body of the patient.
In the observation period by the travel of the pill along the inside of the organs, data for images captured by the pill inside the body is successively transmitted to the outside through wireless communications, and the data is stored on memory. By carrying a receiver including such a wireless communication function and a memory function, the patient can act freely during the observation period since the pill is swallowed until it is excreted. After the observation, a doctor or a nurse displays the image of the organs based on the image data stored on the memory and performs diagnosis.
As for a supply of the power, there are systems such as a battery supply system in which a battery is incorporated in this type of pill, because the pill remains inside the body of the patient, and supplies power to the inside of the pill, and a power transmission system that supplies power to the inside of the body by transmitting the power from the outside of the body of the patient to the pill.
The latter case of the power transmission system has a configuration in which a power receiving antenna is provided in the inside of the pill and power is transmitted to the inside of a radio capsule (corresponding to the pill) through the power receiving antenna to operate the radio capsule remaining in the body of the patient for a long time (see Japanese Patent Application Laid Open No. 2001-231186)
As this type of pill at present, there are M2A (trademark) produced by Given Imaging Ltd. of Israel and NORIKA (trademark) produced by Kabushiki Kaisha RF of Japan, which have already entered into its practical stage.
As explained above, the conventional power transmission system only supplies power from the outside of the body, and therefore, the operation of the pill cannot be controlled from the outside of the body. Since the pill itself consumes power constantly under any circumstances, a predetermined level or more power should be continuously transmitted thereto.